Pump



G. T. HANSEN AND C. F. SHERWOOD. PUMP.

APPLICATION FILED APR. 28. 1919.

1,38QQ7Q8. Patented June 7 1921.

3 SHEETSSHEET I.

G. T. HANSEN AND 0. F. SHERWOOD.

PUMP.

APPLICATION FILED APR. 28,1919.

1,38@ ?98 Patented June 7, 1921.

3 SHEETSSHEET 2.

Q7 5 2/ it I .35 4? @Y: 7 2 I: I

5/ *f I L V [72067275715 @[IAQZSQE/ 5602 6 Tfiarzaezz I C/mfZcsFJ/zerwoad G. T. HANSEN AND C. F. SHERWOOD.

PUMP.

APPLICATION FILED APR. 28. 1919.

1,380,798, Patented June 7, 192i 3 sHEEIs-sHEET 3.

UNHT r rte GEORGE 'r. HAnsEirAnn CHARLES r, SHERWOOD, or saw LECITY/UTAH.

PUBEP.

Specification of'Letters Patentah Patented June "Z, 1921.

Application filed, April as, 1919. Serial No. 293,295.

To all whom it may concern Be it known that we, GEORGE T. HAiNsEN andCHARLES F. SHERWOOD, both citizens of the United States, residing atSalt Lake City, in the county of Salt Lake and State of Utah, haveinvented a certain new and use ful Improvement in Pumps, of which thefollowing is a full, clear, concise, and exact description, referencebeing had to the accompanying drawings, forming a part of thisspecification. A

This invention relates to pumps.

The invention has particular reference to that class of pumps employedin pumping fluids containing gritty or abrasive material. Rotary sandpumps are exemplary of this class of pumps, or as affording a stillbetter example of a pump to which the invention is particularlyapplicable, reference is made to the rotary pump used in pumping thetailings or gangue from ore separating apparatus. The tailings is therefuse left after the ore separating process has been completed and isusually composed of a suspension liquid such as water and.

. from their original shape and as the clearance areas between theimpeller and the casing become enlarged through the abrasion of theirsurfaces. We have conceived that this difliculty could be overcome orgreatly relieved by protecting or rendering more durable the exposedsurfaces of the impeller element, as well as the exposed surfaces in theinterior of the pump casing. Heretofore, it has been proposed to usemetallic surfaces of hard metal, such as manganese steel. But such hardmetal wears away rapidly. It has'also been proposed to use a resilientlining for the pump casing, preferably one of rubber, such as isdisclosed in the patent to Jones, No. 888,814. This resilient lining hasbeen attended with marked success, which may be explained by the factthat the rubber will yield at each point ofimpact before it will sufferabrasion by the impinging particles of ore. Neither of these methods,however, make any provision for the wear of the impeller member, thepractice heretofore being to substitute a new impeller member for theworn one as often as necessary.

We have found that in the use of an ordinary metallic impeller with arubber lined casing there is a tendency for particles caught at theedges ofthe impeller to tear the rubber, and also for the abrasiveparticles to become embedded in the rubber and score the unyieldingmetallic surface of the impeller.

To maintain the original shape of the impeller, to retain the originalclearance, and v to prevent wear between the adjacent surfaces of thecasing and impeller, we propose to applya resilient covering over thesurface of the impeller, in addition to the resilient lining in thecasing. We find that two resilient surfaces subject to the flow of anabrasive material between them will possess a "greater durability thantwo metallic surfaces, or one metallic surface and one resilientsurface.

We have also devised an improved meth-.

od ofapplying the protective lining to the interior of the pump casing.This improved method holds the resilient lining securely in place andfacilitates the insertion and removal of the lining.

In the accompanying drawings the invention is illustrated as applied toa tailin-gs pump of the type above described, though, as previouslystated, the invention is broadly applicable to pumps in general forpumping fluids containing abrasive material. It will also be apparentthat the invention may be advantageously adapted to the rotor oroperating elements of difi'erent classes of machinery subject to erosionby abrasive materials, or subject to the impingement of fluids moving athigh velocities.

In the drawings:

Figure l is a transverse sectional view through a rotary pump of theopen'runner type illustratingthe application of the invention thereto;

Fig. 52 is an end elevational view of' the same with the front half ofthe casing removed;

Fig. 3 is an enlarged sectional view taken on the line 3-8 of Fig. 2;

Fig. 4 is an end elevational view of a rotary pump of the closed runnertype;

Fig. 5 is a sectional view taken on the line .55 of Fig. 4:;

Fig. 7 is a view illustrating the manner of protecting the inlet conduitto the rotary pump and the exposed surfaces of the valve interposedinthis conduit.

Referring first to the open runner type of pump illustrated in Figs. 1,2 and 3, it will be noted that the metallic casing 2 of the pump issplit intothe front and rear halves 3 and 4 respectively, which arejoined by bolts 5 passing through bolting flanges 6 and 7 extendingaround the circumference of the casing section. The casing as a whole issupported upon a cylindrical shaft housing 8, to which the casing isbolted, as indicated, the housing 8 comprising part of a suitablepedestal bearing or the like, not shown. A bearing sleeve 9, in thecylindrical housing 8, affords abearing for the impeller shaft 10.

The front section 3 of the casing is provided with a central intakeopening 11. A tailings pipe 12, leading from a separator box or othersource, has communication with the central intake 11 through an elbowfitting 13 which is bolted-to the tailings conduit 12 and to the frontcasingsection 8. A discharge outlet 14: leads tangentially from thecircular chamber in the interior of the casing 2, and has suitableconnection with a discharge conduit 15.

The open runner or impeller, which is broadly designated 16, comprises acentral hub 17 mounted on the driving shaft 10, and a series of impellerblades 21 radiating therefrom. The sectional formation of these impellerblades is illustrated in Fig. 3 and consists of a web portion 22 and aright angle flange 23 formed along the' trailing edge of the web portion22, as shown in Fig. 2. These flanges form pockets on the intake side ofthe impeller blade 21, into which the pulp or tailings is deliveredthrough the intake opening 11. The inner ends of the flan 'es 23 arechamfered off, as indicated, to fac1litate the flow of the pulp intothese pockets. The centrifugal force created by the rotating impeller 16will obviously impel the pulp outward into the annular passageway '24from whence it will be discharged out through the discharge outlet 14.

The resilient lining which we employ for pretecting the'interior of thecasing 2, is divided into two separate sections 25 and 26, each of thesesections being preferably molded to conform to the interior surfaces ofits respective casing section. These lining sections may be attached tothe interior of the casing 2 by a clamping arrangement similar to thatillustrated in the Jones patent hereinbefore mentioned, or by cementingto the surfaces of the casings, or by vulcanmemes izing directly to themetallic surfaces of the casings. A method which we find preferable toany of these, however, is that of applying the resilient lining to athin metallic form or backing, which has been previously pressed intothe shape of the casing, the combined lining, consisting of the ressedmetallic form and the resilient linmg thereon, being then placed in thecasing. These metallic forms are indicated at 27 and 28, and preferablyconsist of thin sheet steel plates which have been pressed into theconformation of their respective casing sections under a hydraulicpress. A suitable grade of soft, tough rubber is the most desirablematerial for this resilient lining. The preferred method of securing theresilient lining to the sheet steel form is to first paint the surfaceof the form with a vulcaniz ing adhesive fluid and then vulcanize therubber over this coating. The complete lining section is then fittedsnugly into thev casing section where it is held by the bolting togetherofthe two casing sections.

The protective rubber covering 30, which sheaths the surfaces of theimpeller 16, may be applied in several ways. method is to place theimpeller in a suitable mold and mold the rubber covering 30 upon thesurfaces of the impeller. This method possesses the advantage of alwaysapplying the same thickness of rubber upon the impeller blades so thatthe calculated clearance between the impeller and easing lining will notvary. The rubber covering 30 is extended over the hub 17 and allsurfaces of One preferred the impeller likely to be exposed to theabrasive action of the moving pulp. A vulcanizin liquid or the like maybe used to assist in rmly securing the rubber covering 30 over theentire area of the impeller.

Practice has demonstrated that the amount ofabrasion which results fromthe impingement of the grit particles upon the resilient surfaces, orfrom their frictional wear in moving across these surfaces, ispractically negligible as compared with that of the hard metallicsurfaces. This is due to the elasticity of the layer of rubber, whichwill yield before it will suffer abrasion. It will be obvious from thisaction of the rubber surface that any particles of rock or quartz caughtbetween the sides of the impeller and the interior of the casing willnot score the surfaces but will be depressed into the yielding rubberuntil they can work out from between the impeller and easing.

Figs. 4:, 5 and 6 illustrate the invention as applied to a closed runnertype of rotary pump. The general construction and operation of this typeof pump is substantially the same as the pump just described. The pumpcasing 2 comprises the separable seccumferential bolting flanges 6 and7. The

intake is through the elbow 13 and the dismanner as with the open runnertype.

this case the elbow 13 is formed with an integral cover plate 32, whichis bolted to a circular opening in. the front tion 3'.

The runner or impeller 33 comprises a pair of circular plates 34 and 35spaced by a series of curved impeller blades 36. The blades36 projectlaterally from the face of the rear plate 34, with which they are formedintegral. This rear plate 34 is rigidly mounted upon the impeller shaft10' and is formed with a forwardly projecting hub 37. The ,front plate35 is removable from the impeller and is normally secured casingsecthe'reto by a spider or hollow hub 38, which projects back and isbolted to the end of'the boss 37. The front plate 35 has a centralopening communicating with the passageway inthe elbow 13', andthe member38 has radial openings 39, affording communica-.

tion between this opening and the interior of the impeller 33. Bothplates 34 and 35 have openings 41 therein between the blades 36, forproducing a circulation of fluid up.

through the clearance areas between the impeller 33 and the rubber linedcasing 2.

The rubber liner sections 25 and 26 are constructed of the pressed steelform and layer of rubber vulcanized thereto, precisely the sameashereinbefore described. The in-' ner surface of the front cover plate 32has an individual rubber lining consisting of the layer of rubber 42 andthe pressed steel form 43 which are extensive of the rubber liner 43 andsteel form 42' in theelbow 13.

The entire surface of the plate 34 is sheathed with a protective layerof rubber 44, which extends out and also includes the surfaces of theimpeller blades 36, asindi cated at 45 (Fig. 6). The front plate 35 issheathed with an individual protective layer of rubber 46 so as topermit removal of this plate from the front of the impeller 33.

We also contemplate providing the intake conduit 12 and its .difierentfittings with our improved protective lining, as will be noted fromFigs. 1 and.5. We find the use of this protective resilient lining to beof decided advantage for protecting the interior of the. conduitsconveying the. tailings' to and from the pump, and particularly forprotecting the interior of the conduit at bends and c1.- bows, and alsothe exposed surfaces of valves and other fittings in the conduits. InFig. 7 we have illustrated this adaptation of our invention as appliedto the intake conduit 12' leading to the" rotary pump just described.The conduit 12' is shown as comprising a plurality of conduit sections50, preferably connected by bolting flanges, 51.

The interior of each conduit section is-fittedwith an individual rubberliner 52 vulcanized to a pressed steel form 53,so as to be readilyremovable from the conduit section? The elbow fitting 54 is similarlyproyided with a rubber liner 5 5 backed bythe pressed steel form 56. Itwill be apparent that the outer curved surface in. the elbow' conduit 54will be subject to a more severe abrasion from the impingement of theabrasive particles as they are deflected from one course of travel toanother. To provide for the renewal of the resilient lining at. thispoint without the necessity of unbolting the elbow 54 from the rest ofthe conduit, we have provided a removable'plug 58, which seats in a boss59 formed in the elbow 541 The plug is held in place by bolts 60engagingin cooperating flanges 61 and 62 on the plug 58 and boss 59. The innerend of the plug 58 is curved in conformation with the curved passage inthe elbow 54 and is faced with a rubber facing 63 vulcanized directlytothe plug. The feature of applying a resilient pad or facing at thecorner of a conduit conveying abrasive materials, is, we believe,broadly new. We contemplate the application of this idea to ashconveyers and the like.

We have illustrated a gate valve 65 interposed in the conduit 12 forthrottling or completely stopping the intake flow of tailings to thepumpP. The closure surfaces of a valve interposed in a conduit conveyingmaterial of this character are usually sub-- ject'to a severe cutting bythe impingement of the abrasive material, particularly when the valvemember is in a throttlin position. We have remedied this condition%oyfacing the closure surfaces of the valve member .with a resilientcovering of rubber from which the impinging particles merely rebound.The valve gate 66 is of wedge for;

mation and is arranged to fit ina c0rresponding wedge seat provided inthe conduit passageway. A screw 67 and hand wheel 68 are'arrangedtoraise or lower the wedge gate 66in an obvious manner. Uponthe wedge surfaces of the gate '66 we have applied a rubber facing orcovering 69, which may be either vulcanizeddirectly to the gate ormounted upon a pressed steel backing which may be suitably secured tothe gate. Theprotective covering 69 is extended around the side edges ofthe gate as well, and especially around the lower edges of the gate,which are particularly subject. to cuttin when the gate is in throttlingposition. he resiliency of the rubber facing on the valve gate willalways insure a tight fit in the valve seat. j

The use of a resilient material for protecting the exposed metallicsurfaces in the present invention, extends to all materials havingthedesired characteristics, such as leather, or a composition of rubber andfabric, or any other suitable material. Rubber is the preferredmaterial, however, owing to its greater resiliency and to the lowcoefficient of friction between the water and the rubber when in a wetcondition. The rubber, furthermore, protects the metallic surfaces ofthe pump and other lined parts against the corrosive action of the acidsoften contained in the tailings or refuse pulp.

It will also be apparent. that other methods of attaching the resilientmaterial may be employed, such'as by cement or any suitable adhesivematerial.

We claim:

1. In a centrifugal pump for pumping a liquid containing abrasivematerial, a casing having an axial inlet and a peri heral outlet, saidcasing being divided on a p ane substantially at right angles to theaxis of the pump, an impeller within the casing comprising a hub, adriving shaft secured to the hub, said impeller comprising a rigid flatportion lying, in a plane at substantiallyv right angles to "the axis ofthe shaft, and a plurality of rigidintegral flanges forming vanes andextendinggenerally radially and lying at right angles to the flatportion, said flat portion I and said flanges being completely coatedwith rubber secured perma-- nentl to the surfaces of the same and aremova 1e liner of rubber having a flexible sheet metal backing fittinthe interior surfaces of said casing, said liner being divided onsubstantially the same plane as the casing, the partsof said liner beingremovable laterally from the interior of the casingfor repair orreplacement, said impeller having its rigid portion lying between thetwo casing sections and partly in each.

2. In a centrifugal pump, a casing having an axial inlet, and aperipheral outlet, said casing being divided on a central planesubstantially at right angles to the axis and having flanges forsecuring the two" parts together, a lining forthe interior of the pumpcomprising a relatively thin flexible sheet metal backing and a rubberfacing, said lining covering substantially the entire interior surfaceof the pump casing and being divided on substantially the same plane asthe casin and each half being capable of being with rawn laterally fromthe correr' sponding casin section.

3. In a centrlfugalpump, a snail shell casing hav ng an-axial inlet anda" tangential outlet, at lining for substantiallysthe entire innersurface of the casing, said casing being divided centrally on a plane atsubstantially right angles to the axis of the casing and said liningbeing divided into two parts on substantially the same plane, saidlining comprising a thin sheet metal backing adapted to lie against theinside of the easing and a rubber facing each half of said lining havingan axial tubular portion, one for an opening and the other for a shaft.the surface 0 aser/es opening, and each half having a tangentialportion fittingthe tangential outlet of the casing, said halves of thelining being held together edge to edge by theclamping together of thecasinghalves. I

4:. In a pump for pumping an abrasive material, the combination of acasing, an impeller .in said casing formed of a metallic wheel structurecomprisin a hub, a plurality of metallic blades pro' ecting therefromand having impelling surfaces, said metallic blades being formedintegrally with said hub, a web construction joining said blades withsaid hub, and a continuous covering of rubber over the outer surfaces ofsaid blades and over said web construction for preventing the abrasionor corrosion of the metallic structure thereof. v

5. Ina pump for pumping an abrasive material, the combination of acasing, a closed impeller in said casing comprising a rear, circularmetallic plate, a hub formed on said plate for mounting the latter on apump shaft,- a plurality of metallic impeller vanes formed integrallywith said rear plate and projecting forwardly from the face thereof, afront circular metallic plate for closing off the open, side of saidimpeller vanes, said front plate having a central admission openingforadmitting the fluid to the vanes between said plates, screw means forfastening said front plate against said vanes, a protective covering ofrubber molded over the exposed surfaces of said rear plate and saidimpeller vanes, and an independent protective covering of rubber moldedover, the exposed surfaces of said front plate, said latter coverinbeing independent of the covering ofru her on said vanes and rear plateto permit removal of said front plate.

6. In a pump for pumping a fluid having an abrasive characteristic, apump casing, said casing'being divided into sections, a protectivelining in said casing, said lining being divided into sections fittlnginto said casing sections, each sectionofsaid l1n1ngbe-- ing composed ofathinsheet steel form pressed to conform to the interior of its corresponding casing section, a rubber facing of relatively reaterthickness vulcanized to I said form and exposed to the impingement ofthe abrasive material, said sheet steel form being sufficiently thin andductile to permit of its being pressed into close engagement with thevarious surfaces of said pump casing. p In witness whereof I, GEORGE 'I.HANSEN, subscribe my name this 24th day of March,

CHARLES FJSHERWQOD.

